﻿/******************************************************************************************************
Copyright (c) 2014 Steven Giacomelli (stevegiacomelli@gmail.com)

Permission is hereby granted, free of charge, to any person obtaining a copy of this
software and associated documentation files (the "Software"), to deal in the Software
without restriction, including without limitation the rights to use, copy, modify,
merge, publish, distribute, sublicense, and/or sell copies of the Software, and to
permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies
or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE
FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
******************************************************************************************************/

using System;

namespace SharpGeo
{
    /// <summary>
    /// The base class for all Geometric Data Elements
    /// </summary>
    abstract public class Geometry :
        IEquatable<Geometry>
    {
        #region Constructor

        /// <summary>
        /// Constructs a new Geometry object
        /// </summary>
        /// <param name="uniqueId">The UniqueID of this Geometry</param>
        protected Geometry(Guid uniqueId)
        {
            UniqueId = uniqueId;
            Envelope = Envelope.Empty;
        }

        #endregion Constructor

        #region Fields

        private GeometryAttributes _attributes = new GeometryAttributes();

        #endregion Fields

        #region Properties

        /// <summary>
        /// Gets the UniqueID of this Geometry
        /// </summary>
        public Guid UniqueId { get; protected set; }

        /// <summary>
        /// Gets the Envelope of this Geometry
        /// </summary>
        public Envelope Envelope { get; protected set; }

        /// <summary>
        /// Gets the attributes associated with this Geometry
        /// </summary>
        public GeometryAttributes Attributes { get { return _attributes.AsReadOnly; } }

        #endregion Properties

        #region Methods

        /// <summary>
        /// Sets the attributes of this object
        /// </summary>
        /// <param name="attributes">The new attributes of this object</param>
        public void SetAttributes(GeometryAttributes attributes)
        {
            if (attributes != null)
            {
                _attributes.SetAttributes(attributes);
            }
        }

        /// <summary>
        /// Compares two Geometry objects for equality
        /// </summary>
        /// <param name="obj">The other Geometry to compare</param>
        /// <returns>True if both Geometries are equal</returns>
        public override bool Equals(object obj)
        {
            if (obj == null || GetType() != obj.GetType())
                return false;

            return ((Geometry)obj).Equals(this);
        }

        /// <summary>
        /// Compares two Geometry objects
        /// </summary>
        /// <param name="other">The other Geometry object to compare</param>
        /// <returns>True if both Geometries are equal</returns>
        public bool Equals(Geometry other)
        {
            if (other == null)
                return false;

            //compare solely on the basis of the unique ID
            return other.UniqueId == UniqueId;
        }

        /// <summary>
        /// Computes the hashcode of this Geometry
        /// </summary>
        /// <returns>The computed hashcode</returns>
        public override int GetHashCode()
        {
            return UniqueId.GetHashCode();
        }

        /// <summary>
        /// Converts this Geometry to a string
        /// </summary>
        /// <returns>A string representing this Geometry</returns>
        public override string ToString()
        {
            return UniqueId.ToString();
        }

        #endregion Methods
    }
}